1. Field of the Invention
The invention relates to a method for controlling a resultant motion, consisting of component movements along a plurality of coordinate axes, of a machine element between two points in space in accordance with selectively variable override values (i.e., ratios of desired velocities of the machine element to a predetermined normal operating velocity of the element, the ratios preferably being expressed as percentages of the normal operating velocity).
2. Related Art
As a rule, movement of the tools of a machine tool or the hand of a robot involves movement along more than one coordinate axis; so that the resulting motion path is obtained from the superimposed individual motions. This complex motion is established by the program of the machine tool or by the numerical control unit controlling the robot, usually in accordance with the normal operating velocity of the system provided in the production process. If, for instance, a robot is to be run in slow motion for testing purposes, the velocities of movement along the coordinate axes are limited to an adjustable percentage of the normal velocity by means of a so-called override generator. Such limitation of the velocity, however, leads to the situation that the resultant path travelled during the motion process differs from the resultant path that would be traveled at normal operating velocity.